[PATCH v4 2/9] x86, pci: Abstract PCI config accessors and use AMD Fam10h workaround exclusively.

From: Tomasz Nowicki
Date: Wed Mar 11 2015 - 10:15:33 EST


>From now on, readb()/writeb()/etc. generic calls are used as default
approach. Special MMIO accessors are registered for AMD Fam10h CPUs only.

Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
---
arch/x86/include/asm/pci_x86.h | 8 +++
arch/x86/pci/mmconfig-shared.c | 114 +++++++++++++++++++++++++++++++++++++++++
arch/x86/pci/mmconfig_32.c | 24 +--------
arch/x86/pci/mmconfig_64.c | 24 +--------
arch/x86/pci/numachip.c | 24 +--------
5 files changed, 128 insertions(+), 66 deletions(-)

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index d024f4d..c57c225 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -137,6 +137,11 @@ struct pci_mmcfg_region {
char name[PCI_MMCFG_RESOURCE_NAME_LEN];
};

+struct pci_mmcfg_mmio_ops {
+ u32 (*read)(int len, void __iomem *addr);
+ void (*write)(int len, void __iomem *addr, u32 value);
+};
+
extern int __init pci_mmcfg_arch_init(void);
extern void __init pci_mmcfg_arch_free(void);
extern int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
@@ -145,6 +150,9 @@ extern int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
phys_addr_t addr);
extern int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
+extern u32 pci_mmio_read(int len, void __iomem *addr);
+extern void pci_mmio_write(int len, void __iomem *addr, u32 value);
+extern void pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops);

extern struct list_head pci_mmcfg_list;

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index dd30b7e..8b3bc4f 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -31,6 +31,118 @@ static DEFINE_MUTEX(pci_mmcfg_lock);

LIST_HEAD(pci_mmcfg_list);

+static u32
+pci_mmconfig_generic_read(int len, void __iomem *addr)
+{
+ u32 data = 0;
+
+ switch (len) {
+ case 1:
+ data = readb(addr);
+ break;
+ case 2:
+ data = readw(addr);
+ break;
+ case 4:
+ data = readl(addr);
+ break;
+ }
+
+ return data;
+}
+
+static void
+pci_mmconfig_generic_write(int len, void __iomem *addr, u32 value)
+{
+ switch (len) {
+ case 1:
+ writeb(value, addr);
+ break;
+ case 2:
+ writew(value, addr);
+ break;
+ case 4:
+ writel(value, addr);
+ break;
+ }
+}
+
+static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_default = {
+ .read = pci_mmconfig_generic_read,
+ .write = pci_mmconfig_generic_write,
+};
+
+static struct pci_mmcfg_mmio_ops *pci_mmcfg_mmio = &pci_mmcfg_mmio_default;
+
+static u32
+pci_mmconfig_amd_read(int len, void __iomem *addr)
+{
+ u32 data = 0;
+
+ switch (len) {
+ case 1:
+ data = mmio_config_readb(addr);
+ break;
+ case 2:
+ data = mmio_config_readw(addr);
+ break;
+ case 4:
+ data = mmio_config_readl(addr);
+ break;
+ }
+
+ return data;
+}
+
+static void
+pci_mmconfig_amd_write(int len, void __iomem *addr, u32 value)
+{
+ switch (len) {
+ case 1:
+ mmio_config_writeb(addr, value);
+ break;
+ case 2:
+ mmio_config_writew(addr, value);
+ break;
+ case 4:
+ mmio_config_writel(addr, value);
+ break;
+ }
+}
+
+static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_amd_fam10h = {
+ .read = pci_mmconfig_amd_read,
+ .write = pci_mmconfig_amd_write,
+};
+
+void
+pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops)
+{
+ pci_mmcfg_mmio = ops;
+}
+
+u32
+pci_mmio_read(int len, void __iomem *addr)
+{
+ if (!pci_mmcfg_mmio) {
+ pr_err("PCI config space has no accessors !");
+ return 0;
+ }
+
+ return pci_mmcfg_mmio->read(len, addr);
+}
+
+void
+pci_mmio_write(int len, void __iomem *addr, u32 value)
+{
+ if (!pci_mmcfg_mmio) {
+ pr_err("PCI config space has no accessors !");
+ return;
+ }
+
+ pci_mmcfg_mmio->write(len, addr, value);
+}
+
static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
{
if (cfg->res.parent)
@@ -231,6 +343,8 @@ static const char *__init pci_mmcfg_amd_fam10h(void)
return NULL;
}

+ pci_mmconfig_register_mmio(&pci_mmcfg_mmio_amd_fam10h);
+
return "AMD Family 10h NB";
}

diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
index 43984bc..4b3d025 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -71,17 +71,7 @@ err: *value = -1;

pci_exp_set_dev_base(base, bus, devfn);

- switch (len) {
- case 1:
- *value = mmio_config_readb(mmcfg_virt_addr + reg);
- break;
- case 2:
- *value = mmio_config_readw(mmcfg_virt_addr + reg);
- break;
- case 4:
- *value = mmio_config_readl(mmcfg_virt_addr + reg);
- break;
- }
+ *value = pci_mmio_read(len, mmcfg_virt_addr + reg);
raw_spin_unlock_irqrestore(&pci_config_lock, flags);
rcu_read_unlock();

@@ -108,17 +98,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,

pci_exp_set_dev_base(base, bus, devfn);

- switch (len) {
- case 1:
- mmio_config_writeb(mmcfg_virt_addr + reg, value);
- break;
- case 2:
- mmio_config_writew(mmcfg_virt_addr + reg, value);
- break;
- case 4:
- mmio_config_writel(mmcfg_virt_addr + reg, value);
- break;
- }
+ pci_mmio_write(len, mmcfg_virt_addr + reg, value);
raw_spin_unlock_irqrestore(&pci_config_lock, flags);
rcu_read_unlock();

diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index bea5249..032593d 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -42,17 +42,7 @@ err: *value = -1;
goto err;
}

- switch (len) {
- case 1:
- *value = mmio_config_readb(addr + reg);
- break;
- case 2:
- *value = mmio_config_readw(addr + reg);
- break;
- case 4:
- *value = mmio_config_readl(addr + reg);
- break;
- }
+ *value = pci_mmio_read(len, addr + reg);
rcu_read_unlock();

return 0;
@@ -74,17 +64,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
return -EINVAL;
}

- switch (len) {
- case 1:
- mmio_config_writeb(addr + reg, value);
- break;
- case 2:
- mmio_config_writew(addr + reg, value);
- break;
- case 4:
- mmio_config_writel(addr + reg, value);
- break;
- }
+ pci_mmio_write(len, addr + reg, value);
rcu_read_unlock();

return 0;
diff --git a/arch/x86/pci/numachip.c b/arch/x86/pci/numachip.c
index 2e565e6..5047e9b 100644
--- a/arch/x86/pci/numachip.c
+++ b/arch/x86/pci/numachip.c
@@ -51,17 +51,7 @@ err: *value = -1;
goto err;
}

- switch (len) {
- case 1:
- *value = mmio_config_readb(addr + reg);
- break;
- case 2:
- *value = mmio_config_readw(addr + reg);
- break;
- case 4:
- *value = mmio_config_readl(addr + reg);
- break;
- }
+ *value = pci_mmio_read(len, addr + reg);
rcu_read_unlock();

return 0;
@@ -87,17 +77,7 @@ static int pci_mmcfg_write_numachip(unsigned int seg, unsigned int bus,
return -EINVAL;
}

- switch (len) {
- case 1:
- mmio_config_writeb(addr + reg, value);
- break;
- case 2:
- mmio_config_writew(addr + reg, value);
- break;
- case 4:
- mmio_config_writel(addr + reg, value);
- break;
- }
+ pci_mmio_write(len, addr + reg, value);
rcu_read_unlock();

return 0;
--
1.9.1

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